1 All the numerical options, if not specified otherwise, accept a string
2 representing a number as input, which may be followed by one of the SI
3 unit prefixes, for example: 'K', 'M', or 'G'.
5 If 'i' is appended to the SI unit prefix, the complete prefix will be
6 interpreted as a unit prefix for binary multiplies, which are based on
7 powers of 1024 instead of powers of 1000. Appending 'B' to the SI unit
8 prefix multiplies the value by 8. This allows using, for example:
9 'KB', 'MiB', 'G' and 'B' as number suffixes.
11 Options which do not take arguments are boolean options, and set the
12 corresponding value to true. They can be set to false by prefixing
13 the option name with "no". For example using "-nofoo"
14 will set the boolean option with name "foo" to false.
16 @anchor{Stream specifiers}
17 @section Stream specifiers
18 Some options are applied per-stream, e.g. bitrate or codec. Stream specifiers
19 are used to precisely specify which stream(s) a given option belongs to.
21 A stream specifier is a string generally appended to the option name and
22 separated from it by a colon. E.g. @code{-codec:a:1 ac3} contains the
23 @code{a:1} stream specifier, which matches the second audio stream. Therefore, it
24 would select the ac3 codec for the second audio stream.
26 A stream specifier can match several streams, so that the option is applied to all
27 of them. E.g. the stream specifier in @code{-b:a 128k} matches all audio
30 An empty stream specifier matches all streams. For example, @code{-codec copy}
31 or @code{-codec: copy} would copy all the streams without reencoding.
33 Possible forms of stream specifiers are:
35 @item @var{stream_index}
36 Matches the stream with this index. E.g. @code{-threads:1 4} would set the
37 thread count for the second stream to 4.
38 @item @var{stream_type}[:@var{stream_index}]
39 @var{stream_type} is one of following: 'v' for video, 'a' for audio, 's' for subtitle,
40 'd' for data, and 't' for attachments. If @var{stream_index} is given, then it matches
41 stream number @var{stream_index} of this type. Otherwise, it matches all
43 @item p:@var{program_id}[:@var{stream_index}]
44 If @var{stream_index} is given, then it matches the stream with number @var{stream_index}
45 in the program with the id @var{program_id}. Otherwise, it matches all streams in the
47 @item #@var{stream_id}
48 Matches the stream by a format-specific ID.
51 @section Generic options
53 These options are shared amongst the ff* tools.
60 @item -h, -?, -help, --help [@var{arg}]
61 Show help. An optional parameter may be specified to print help about a specific
64 Possible values of @var{arg} are:
66 @item decoder=@var{decoder_name}
67 Print detailed information about the decoder named @var{decoder_name}. Use the
68 @option{-decoders} option to get a list of all decoders.
70 @item encoder=@var{encoder_name}
71 Print detailed information about the encoder named @var{encoder_name}. Use the
72 @option{-encoders} option to get a list of all encoders.
74 @item demuxer=@var{demuxer_name}
75 Print detailed information about the demuxer named @var{demuxer_name}. Use the
76 @option{-formats} option to get a list of all demuxers and muxers.
78 @item muxer=@var{muxer_name}
79 Print detailed information about the muxer named @var{muxer_name}. Use the
80 @option{-formats} option to get a list of all muxers and demuxers.
88 Show available formats.
91 Show all codecs known to libavcodec.
93 Note that the term 'codec' is used throughout this documentation as a shortcut
94 for what is more correctly called a media bitstream format.
97 Show available decoders.
100 Show all available encoders.
103 Show available bitstream filters.
106 Show available protocols.
109 Show available libavfilter filters.
112 Show available pixel formats.
115 Show available sample formats.
118 Show channel names and standard channel layouts.
120 @item -loglevel [repeat+]@var{loglevel} | -v [repeat+]@var{loglevel}
121 Set the logging level used by the library.
122 Adding "repeat+" indicates that repeated log output should not be compressed
123 to the first line and the "Last message repeated n times" line will be
124 omitted. "repeat" can also be used alone.
125 If "repeat" is used alone, and with no prior loglevel set, the default
126 loglevel will be used. If multiple loglevel parameters are given, using
127 'repeat' will not change the loglevel.
128 @var{loglevel} is a number or a string containing one of the following values:
131 Show nothing at all; be silent.
133 Only show fatal errors which could lead the process to crash, such as
134 and assert failure. This is not currently used for anything.
136 Only show fatal errors. These are errors after which the process absolutely
137 cannot continue after.
139 Show all errors, including ones which can be recovered from.
141 Show all warnings and errors. Any message related to possibly
142 incorrect or unexpected events will be shown.
144 Show informative messages during processing. This is in addition to
145 warnings and errors. This is the default value.
147 Same as @code{info}, except more verbose.
149 Show everything, including debugging information.
152 By default the program logs to stderr, if coloring is supported by the
153 terminal, colors are used to mark errors and warnings. Log coloring
154 can be disabled setting the environment variable
155 @env{AV_LOG_FORCE_NOCOLOR} or @env{NO_COLOR}, or can be forced setting
156 the environment variable @env{AV_LOG_FORCE_COLOR}.
157 The use of the environment variable @env{NO_COLOR} is deprecated and
158 will be dropped in a following FFmpeg version.
161 Dump full command line and console output to a file named
162 @code{@var{program}-@var{YYYYMMDD}-@var{HHMMSS}.log} in the current
164 This file can be useful for bug reports.
165 It also implies @code{-loglevel verbose}.
167 Setting the environment variable @code{FFREPORT} to any value has the
168 same effect. If the value is a ':'-separated key=value sequence, these
169 options will affect the report; options values must be escaped if they
170 contain special characters or the options delimiter ':' (see the
171 ``Quoting and escaping'' section in the ffmpeg-utils manual). The
172 following option is recognized:
175 set the file name to use for the report; @code{%p} is expanded to the name
176 of the program, @code{%t} is expanded to a timestamp, @code{%%} is expanded
180 Errors in parsing the environment variable are not fatal, and will not
181 appear in the report.
183 @item -cpuflags flags (@emph{global})
184 Allows setting and clearing cpu flags. This option is intended
185 for testing. Do not use it unless you know what you're doing.
187 ffmpeg -cpuflags -sse+mmx ...
188 ffmpeg -cpuflags mmx ...
189 ffmpeg -cpuflags 0 ...
191 Possible flags for this option are:
226 @item Specific Processors
243 These options are provided directly by the libavformat, libavdevice and
244 libavcodec libraries. To see the list of available AVOptions, use the
245 @option{-help} option. They are separated into two categories:
248 These options can be set for any container, codec or device. Generic options
249 are listed under AVFormatContext options for containers/devices and under
250 AVCodecContext options for codecs.
252 These options are specific to the given container, device or codec. Private
253 options are listed under their corresponding containers/devices/codecs.
256 For example to write an ID3v2.3 header instead of a default ID3v2.4 to
257 an MP3 file, use the @option{id3v2_version} private option of the MP3
260 ffmpeg -i input.flac -id3v2_version 3 out.mp3
263 All codec AVOptions are obviously per-stream, so the chapter on stream
264 specifiers applies to them
266 Note @option{-nooption} syntax cannot be used for boolean AVOptions,
267 use @option{-option 0}/@option{-option 1}.
269 Note2 old undocumented way of specifying per-stream AVOptions by prepending
270 v/a/s to the options name is now obsolete and will be removed soon.